What Your Blood Type Means For Your Health

New research suggests that blood type could increase your risk of heart disease, Alzheimer's and more.

Quick: What’s your blood type?

If you’re scratching your head, you may be missing out on an important health clue. A spate of recent research suggests that your blood type—whether A, B, AB, or O—may influence your risk for a variety of health conditions, from cardiac disease to cancer.

The research is still early and scientists aren’t yet sure how to explain the connections. Although you can’t change your blood type, however, knowing about added risks can still be helpful. Here are several ways your blood type could be affecting your health—and what to do about it:

Heart disease

“Blood type relates to several diseases including heart attack, stroke, and venous thrombolism,” says Mary Cushman, M.D., a hematologist at the University of Vermont. In fact on average non-O blood groups have a 60-80 percent higher risk than people with blood group O for developing dangerous blood clots, the kind that can break off and travel to the lungs with sometimes devastating results. Similarly people with blood types A, B, or AB are at a greater risk for coronary heart disease than people with blood type O, according to a study from Harvard School of Public Health. Other research has linked non-O blood to greater inflammation, which may help explain the connection.

Don’t fret if you have a blood type other than O, however, Cushman says. Managing heart-related risk factors like high blood pressure and diabetes with lifestyle habits and prescribed medications can tip the scales in the opposite direction, helping keep your ticker in tip-top shape.

Memory problems

A recent study of 30,000 people from the University of Vermont showed that people with the AB blood type were 82 percent more likely than other blood types to develop thinking and memory problems that lead to dementia. “Blood type has been related to diseases like stroke that have a vascular basis so we thought that maybe vascular issues contribute to memory problems,” says Dr. Cushman, who led the study.

Luckily, Dr. Cushman says, the effect was still small. “But it’s important to keep as healthy as possible by controlling high blood pressure, not smoking, staying physically fit and having a healthy diet.” she says. “Each of these can slow the development of memory problems.” It can also help to keep your brain active through things like reading, doing puzzles, and social interaction.

Gastro-intestial conditions

Several studies have found that that people with blood type A have a higher risk of gastric cancer, says investigator Gustaf Edgren, M.D., Ph.D., associate professor of epidemiology at the Karolinska Institute in Sweden. People with type O, on the other hand, are more likely than others to develop peptic ulcer. Since both conditions are associated with a bacteria called h pylori infection, he believes that the findings have to do with different susceptibility to bacterial infections associated with the blood types.

‘There’s little we can do about this regarding gastric cancer,” Dr. Edgren says, “but the risk associated with blood group is actually too small to make much of a difference.” Nevertheless, he says, everyone should try to avoid the three most important risk factors for many diseases: smoking, excessive alcohol consumption, and being overweight.